This application claims priority of Taiwanese Application No. 091215803, filed on Oct. 4, 2002.
1. Field of the Invention
This invention relates to a height-adjustable workpiece feeding device for a wood planing machine, more particularly to a height-adjustable workpiece feeding device with feed-in and take-out rollers which can be moved synchronously in an upright direction relative to a worktable of the wood planing machine.
2. Description of the Related Art
Referring to FIG. 1, a conventional wood planing machine is shown to include a mounting frame 11, a worktable 13 which is movably mounted on the mounting frame 11, a support carriage 12 which is movably mounted above the worktable 13 to confine a working passage 100 therebetween, and rubber feed-in and take-out rollers 141 (only one is shown) which are rotatably and respectively mounted on two sides of the support carriage 12. A height-adjusting member includes four sliding blocks 142 (only two are shown) which are respectively disposed on two ends of the rollers 141, four adjusting rods 143 (only two are shown) which are respectively disposed on top sides of the sliding blocks 142 and which extend outwardly of the mounting frame 11, four screw nuts 144 (only two are shown) which are respectively disposed on the adjusting rods 143, and four adjusting nuts 145 (only two are shown) which are respectively disposed on top ends of the adjusting rods 143.
When it is desired to adjust the feed-in and take-out rollers 141 to a desired height, the adjusting nuts 145 are rotated to move the adjusting rods 143 and the rollers 141 upwardly and downwardly. However, since the adjusting rods 143 are moved separately by means of the adjusting nuts 145, it is difficult to maintain the two ends of each of the feed-in and take-out rollers 141 at a same level, and it is likewise difficult to maintain the feed-in and take-out rollers 141 at a same level, thereby requiring calibration, which is time-consuming and inconvenient.
The object of the present invention is to provide a height-adjustable workpiece feeding device for a wood planing machine, which permits convenient height adjustment of feed-in and take-out rollers of the device.
According to this invention, the height-adjustable workpiece feeding device includes a support carriage for supporting a cutter shaft of a wood planing machine thereon. The support carriage has right and left carriage sides which are respectively mounted on right and left sides of a mounting frame and above a worktable, and feed-in and take-out sides opposite to each other in a transverse direction. The support carriage is movable in an upright direction, and has two guideways which are disposed in the feed-in and take-out sides, respectively. Each of the guideways extends in the upright direction.
Two cam follower units are respectively received in the guideways and are respectively slidable along the guideways between upper and lower positions relative to the worktable. Each of the cam follower units has an engaging surface which faces downwardly.
Feed-in and take-out rollers are respectively journalled on the cam follower units so as to be rotatable about a first axis parallel to a cutter axis of the cutter shaft.
A connecting rod unit has two rod ends which are respectively mounted on the feed-in and take-out sides of the support carriage, and which are rotatable about a second axis transverse to the first axis.
Two cam units are respectively secured on the rod ends of the connecting rod. Each of the cam units has a cam surface which includes a first region and a second region that is disposed behind the first region in a clockwise direction about the second axis. As such, the cam units are synchronously rotatable by the connecting rod unit between a first position, where the first regions of the cam units respectively abut against the engaging surfaces of the cam follower units so as to place the cam follower units in the upper position, and a second position, where the second regions of the cam units respectively abut against the engaging surfaces of the cam follower units so as to place the cam follower units in the lower position.
Each of two biasing members is disposed to bias each of the cam follower units towards the cam surface of a respective one of the cam units.